/*

 * Licensed to the Apache Software Foundation (ASF) under one

 * or more contributor license agreements.  See the NOTICE file

 * distributed with this work for additional information

 * regarding copyright ownership.  The ASF licenses this file

 * to you under the Apache License, Version 2.0 (the

 * "License"); you may not use this file except in compliance

 * with the License.  You may obtain a copy of the License at

 *

 *     http://www.apache.org/licenses/LICENSE-2.0

 *

 * Unless required by applicable law or agreed to in writing, software

 * distributed under the License is distributed on an "AS IS" BASIS,

 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

 * See the License for the specific language governing permissions and

 * limitations under the License.

 */

package com.bff.gaia.unified.sdk.util;



import java.io.IOException;



/**

 * Back-off policy when retrying an operation.

 *

 * <p><b>Note</b>: This interface is copied from Google API client library to avoid its dependency.

 */

public interface BackOff {



  /** Indicates that no more retries should be made for use in {@link #nextBackOffMillis()}. */

  long STOP = -1L;



  /** Reset to initial state. */

  void reset() throws IOException;



  /**

   * Gets the number of milliseconds to wait before retrying the operation or {@link #STOP} to

   * indicate that no retries should be made.

   *

   * <p>Example usage:

   *

   * <pre>

   * long backOffMillis = backoff.nextBackOffMillis();

   * if (backOffMillis == Backoff.STOP) {

   * // do not retry operation

   * } else {

   * // sleep for backOffMillis milliseconds and retry operation

   * }

   * </pre>

   */

  long nextBackOffMillis() throws IOException;



  /**

   * Fixed back-off policy whose back-off time is always zero, meaning that the operation is retried

   * immediately without waiting.

   */

  BackOff ZERO_BACKOFF =

      new BackOff() {



        @Override

        public void reset() throws IOException {}



        @Override

        public long nextBackOffMillis() throws IOException {

          return 0;

        }

      };



  /**

   * Fixed back-off policy that always returns {@code #STOP} for {@link #nextBackOffMillis()},

   * meaning that the operation should not be retried.

   */

  BackOff STOP_BACKOFF =

      new BackOff() {



        @Override

        public void reset() throws IOException {}



        @Override

        public long nextBackOffMillis() throws IOException {

          return STOP;

        }

      };

}